1. Field of the Invention
The present invention relates to an organic semiconductor device, and particularly, to an organic semiconductor device having super-lattice structure with insulating layers and conductive layers which are repeatedly provided in an alternate fashion.
2. Related Background Art
Hitherto, the utilization of materials in the technical field of semiconductor devices and the technical field of optics has made progress solely in respect of inorganic matters which are relatively easy to handle. This is partly for the reason that the technical progress in the field of organic chemistry has been greatly behind that in the field of inorganic materials.
However, there has been surprising technical progress recently made in the field of organic chemistry, and the development on the inorganic materials is said to be almost approaching a limit. Now, it has been sought after to develop organic materials as new functional materials that can exceed the inorganic matters. Advantages of organic materials are such that they are inexpensive, can be produced with ease, and can be highly functional. On the other hand, with respect to the thermal resistance and mechanical strength that have been hitherto considered inferior, organic materials having overcome this problem, others have been recently created one after another. Under such technical background, some research institutions have recently proposed to constitute part or all of the constituents (chiefly thin film part) having the functions of integrated circuit devices such as logical elements, memories and photoelectric transducers and optical devices such as microlens arrays and optical waveguides, with use of organic thin films in place of the conventional inorganic thin films, and even proposed to produce molecular electronic devices in which one organic molecule is endowed with the function of a logical element or a memory, and logical elements comprising a living body-related substance (for example, biotips).
In more recent years, it has been disclosed that an organic metallic compound comprising tetracyanoquinodimethane (TCNQ) serving as an electron acceptor, which compound is an amphiphilic charge transfer complex having a long chain alkyl group as a hydrophobic part, such as bis-tetracyanoquinodimethane dococylpyridinium ##STR1## may form a monomolecular film on a water surface, and this monomolecular film may be built up layer by layer to produce a conductive monomolecular built-up film. This conductive monomolecular built-up film can be a conductive material as they show high specific conductance in the direction parallel to the film surface, but acts as an insulating material in the direction perpendicular to the film.
Such a conductive monomolecular built-up film is attracting interests from a viewpoint of, e.g., application in electronic devices as an organic super-lattice conductive material having anisotropy of very large specific conductance, but has not yet been put into such a practical use.
Semiconductor devices chiefly composed of inorganic materials may generally require expensive materials and complicated production processes such as high temperature treatment, which raise a problem that can not be satisfactorily remedied from an economical viewpoint. To solve such a problem, researches have been made semiconductor devices using organic materials, but nothing has been produced as of the present to as far as an economically constructed semiconductor device is concerned.